Thermostat.



E. MOSS.

THERMOSTAT,

APPLICATION FILED JUNE 24, 1909.

1 ,039, 1 74;, Patented Sept. 24, 1912.

SNVENTOR, ERNEST Moss,

57 JWOMDMA UNITED STATES PATENT OFFICE.-

ERNEST moss, or DALLINGTON; cnnrsronnncn, NEW znanm.

mmos'lwr:

To (123 whom. it may concern: I

'Be it known that I, ERNEST. Moss, a sub-- ject'of the King of GreatBritain, residing at Dallington, Christchurch, in the Dominionof NewZealand, have invented a new and useful Thermostat; and I do herebydeclare the=followingto be a full, clear, and! exact description: :ofthe 1 same.

This invention. relates toan improved construction of apparatus forrthepurpose of recording beat, her for giving an. alarm upon. an outbreak offire in its vicinity,-

The invention relates particularly 'to that class ofrappliances in whicha fluid, ex-- pansible under the action of heat, is placed within areceptacle having flexible :sides and connected with electric alarmcircuit making-or breaking apparatus, in order to sound an alarm whenthesidesof-the-reoeptacle expand under the action-of the=expendingfluid."

The invention consists: inan improvedconstruction of such'apparatus," bymeans of-which provision is made for thesounding of a local alarm, asthe temperature begins to rise, and for the sounding of-a second alarm,say situated at a fire station, when the temperature reaches a dangerousdegree.

The invention also consists in other details ofconstruction andarrangement of parts whereby a compact reliable apparatus is provided.

Infully describing the invention, refer ones will be made to theaccompanying sheet of drawings, in which,-

Figure 1 1s a front elevation of the appliance, electric circuitsconnected therewith being indicated by the diagrammatic Fig. 2 is asectional side elevation lines. thereof, taken on the line 22 of Fig. 1.Fig. 3 is a back view of the cover of the appliance showing theoperative parts attached thereto.

The appliance devised consists of a metailic case or box A that isadapted to be fastened to a Wall, ceiling, or other fixture,

and is provided with a metallic cover B 'springy-nature, and areinsulated from the Patented Sept. 24, 1912.

' pension or-contraction of 'the fluid willf."

thereby cause theinner wall D to bulge in ward into the casingor-outward therefrom; Fixed to the center of the flexible wall D is astud or pin Eformed with an overhanging inner end. I Y I Secured to theinside of thecover are themetal arms Fund G which are made of cover andbox, by being vattached' .to-the insulating blocks F and Grespectively." Thesearms are arranged to extend downwardxsothat theirbottom: ends will lie within the range ofmovement of the stud E, and one-a'rm' F is placed so as to lie in front of such stud, and to bekeptin'close contact therewith, while the other arm G is arranged to liebehind the stud away from contact therewith as clearly shown in Fig. 2.The relative positions of these-twoarms I inrelation to the stud areregulated "-by means of the screws Hand J respectively. These'screwspass in' through the box cover B (being suitably insulated therefrom)and o by manipulating them, the distance of the arms from--the stud maybe arranged-at y. will, and the amount of expansionandcoritraction'movement of the wall D necessary to make and breakcontact betweenthe g5 arms and the stud consequently re lated.

The arm F is preferably arrange *to'opcrate the local alarm and it isarranged to complete a closed circuit K with the box A and adapted,'whenbroken, to'operate an alarm relay M. The arm-Gris arranged-to actuatethe main'alarm, and it is placed in open circuit N with such alarm andthe box, through earth, as shown :inwFig. 1,1 or through a metalliccircuit. This arrangement of the arms F and G I prefer, because -Iconsider it best to hold the local circuit closed, since the first alarmis to be given here, and unless the contacts were maintained carefullyan alarm would call attention to the fact that there was trouble. Theleast expansion of the plate D would cause the contact E to leave thearm F and give the alarm. If an open contact were relied upon to givethe first alarm, rusty or imperfect contact might allow the fire to getunder way, without giving an alarm. Moreover, if the battery were out oforder, the open circuit would not work, whereas, with the closedcircuit, a run downvbattery would be at once indicated. There is afurther advantage in the fact that the movearm G thereby closing cuit Nand causing such ment of the plate D in the same direction operates bothalarms. If the fire is only a moderate one the second alarm need not beallowed to operate, but there will be no fail ure of the alarm, becausesome one forgets to turn it in. The increase in the heat takes care ofthe second alarm, ants are I giving their attention to extlnguishi-npthe blaze.

It wi 1 be seen that when the appliance is subjected to a risingtemperature, the fluid within the receptacle C will expand, and as itexpands, will force the wall D and stud E inward into the box. The studE- will then leave the arm F, breaking its circuit and closing the alarmrelay M, and thereby causing such alarm to sound. As the heat increasesand the inward movement of the stud E continues, such stud will engagewith the the main alarm ciralarm to sound, and to continue sounding solong as the heat remains at the same or a higher temperature. Should thetemperature then fall again, the different parts will resume theirnormal positlons again. I

It will be readily understood that by means of the screws H and J, thepositions of the arms F and G may be arranged so that the differentalarms may be caused to sound at anydesired temperature. These screwsfor this purpose may be provided with any approved form of indicatingmechanism by which their positions are thus regulated, say for instance,pointer arms H, J attached to their outer ends, and passing over scalesas, m upon dials fixed to the cover. It will also be apparent that thealarm circuits operated by the movements of the stud It may be bothclosed or open circuits without departing from the spirit of theinvcntion, and merely requiring variations in the arrangement of thearms formation of the stud.

O and l? are the terminals by means oi F- and Gr and the while theattendwhich the respective circuits K and N are connected to the arms Fand GT respectively. These terminals are suitably insulated from the boxA.

R is the earth terminal by means of which the box is arranged as part ofthe respective circuits K and h.

Any number of these appliances may be connected to the same alarmcircuits, suitable indicator boards I being arranged in the well knownmanner to differentiate between alarms actuated by the distinctappliances. Thus, the locality of a fire or of a rise in temperature maybe indicated at the same time as an alarm is given.

What- I do claim as my invention, sure to secure by Letters Patent, is,

In a thermostat, the combination of a metallic casing; a front coverfitting thereon and having a recess in the lower part of its inner face;a flexible inner wall secured over said recess and forming therewith areceptacle; an expensive fluid in said receptacle; a stud secured tosaid flexible vwall and having an angular end portion spaced from saidwall; separate insulating blocks secured at the upper cornersrespectively of the inner face of said cover; spaced approximatelyparallel pending arms secured to said blocks respectively and eachhaving an inclined lower end disposed respectively to "the front and therear of: said angular end of the'stud; regulating screws passing throughsaid cover and engaging said arms respectively; pointer arms on saidscrews respectively; and a scale under each pointer and on the front ofthe cover.

In testimony whereof, l have signed this specification in the presenceof two subscribing witnesses.

and denaunsr Moss.

Witnesses:

C. H.,S'ro1-i an,' Cues. G. Maseru.

